Wales’ capital city will be overtaken by Sheffield, the former industrial city in South Yorkshire, and tie equal 11th with Newcastle.

Cardiff’s economy will also be among the slowest growing of the UK’s top 20 cities over the next 14 years.

Only Birmingham and Liverpool will grow more slowly, the respected US-based McKinsey Global Institute found.

Economic experts last night warned that the findings must serve as a “wake-up call” to Cardiff, which they said had failed to diversify its economic sectors.

Cardiff’s gross domestic product (GDP) – the market value of all goods and services produced within the city – will rise 22% by 2025, from £48bn (in 2007) to £59bn.

By comparison, cities of similar size across the UK will see their economic output increase at almost twice the speed as Cardiff.

Edinburgh is predicted to be the best performing city at 43%, followed by Belfast (42%), Peterborough (40%), Southampton (38%), Bristol (37.5%) and Sheffield (37%).

Professor Robert Huggins, director of the Centre for International Competitiveness at University Wales Institution, Cardiff, wasn’t surprised by the findings.

The key to future growth, Prof Huggins said, was to diversify the economy away from such a strong focus on retail by attracting new financial services.

“Cardiff’s growth has slipped in the last few years compared to some of the other cities in England and Scotland. The problem for Cardiff is that it’s within Wales and Wales is one of the slowest growing regions in the UK,” he said.

“Cardiff needs to diversify, as some English cities have already done, but there still needs to be a national demand in Wales to build up business that use these services.”

Roy Thomas, of Cardiff Business Partnership, added: “Wales is simply in need of gaining a more competitive view of life and Cardiff is the engine of growth – we need to be out there selling our excellent capital city.

“We currently have inadequate strategic direction in driving the city forward on investment. It is the private sector that will bring growth in economic terms and large corporations need to be valued for their contribution and more attracted to what is on offer.”

Created from a database of more than 2,000 metropolitan areas around the world, McKinsey Global Institute assesses the top cities by population and GDP data and identifies changes that will occur from now to 2025.

The top four British cities will continue to be London, Birmingham, Manchester, and West Yorkshire (Leeds urban area), according to the research.